Self adjuster for pull-type clutch

Abstract

A pull-type clutch including a pressing force transmission lever, an inner peripheral end of which is in contact with a retainer connected to a release bearing, and an approximately annular adjusting ring for adjusting clearances produced by wear of the clutch facing and which is in contact with a radial outside end of the lever and screwed into an inner peripheral surface of the clutch cover. An adjuster is provided on an inner surface side of the adjusting ring and causes the adjusting ring to rotate by means of rotation of the adjuster so that the adjusting ring can move axially toward a pressure side. A rotation drive is provided which is driven by the retainer moved in the clutch axial direction by clutch engaging and releasing operations, when the clutch facings are worn, so as to adjust the adjuster.

What is claimed is: 
     
       1. In a pull-type clutch wherein a release bearing is pulled away from a flywheel for releasing a clutch by a release lever connected to a clutch pedal; a self adjuster for said pull-type clutch including a pressing force transmission lever having an inner peripheral end in contact with a retainer connected to said release bearing, a substantially annular adjusting ring for adjusting clearances resulting from wear of clutch facings of said clutch, said adjusting ring being in contact with a radial outside end of said lever and screwed into an inner peripheral surface of a clutch cover, a stay bracket secured to said clutch cover, said stay bracket having two bearing pieces extending to an inner peripheral surface of said adjusting ring with a pre-set distance, in a clutch circumferential direction therebetween, a pin fitting in said bearing pieces, a worm wheel, having a worm screw on its outer peripheral surface, fitted rotatably onto said pin near one of said bearing pieces, external ratchet teeth, for rotation in only one direction, formed on an end face of said worm wheel and fronting toward one of said bearing pieces, a stopper secured to one of said bearing pieces and mating with said external ratchet teeth for preventing said worm wheel from rotating in said one direction, an arm rotor fitted rotatably onto said pin, said arm rotor having an arm at an end of said arm rotor opposite to said external ratchet teeth of said worm wheel and extending to a radial outside of said pin, said arm of said arm rotor being fitted in a recessed part on an outer peripheral surface of said retainer, ratchet mating parts formed on a pressing end face of said arm rotor and formed on a pressing end face of said worm wheel, said ratchet mating parts mating with each other in a rotating direction of said external ratchet teeth and slide relative to each other in a direction opposite said rotating direction, a spring member urging said arm rotor into engagement with said worm wheel, a play mechanism in said recessed part of said retainer for play in the swing of said arm rotor with movement of said retainer, and a rack formed on an inner peripheral surface of said adjusting ring and mating with said worm screw for rotating said adjusting ring. 
     
     
       2. In a pull-type clutch a release bearing is pulled away from a flywheel for releasing a clutch by a release lever connected to a clutch pedal; a self adjuster for said pull-type clutch including a pressing force transmission lever having an inner peripheral end in contact with a retainer connected to said release bearing, a substantially annular adjusting ring for adjusting clearances from wear of clutch facings of said clutch, said adjusting ring being in contact with a radial outside end of said lever and screwed into an inner peripheral surface of a clutch cover, an opening formed on a part of said clutch cover at a place near an inner peripheral surface of said adjusting ring, a stay bracket secured to said clutch cover and having a bearing piece extending in a clutch axial direction from said opening through a diaphragm spring to a vicinity of an inside surface of said adjusting ring, a pin extending in a clutch radial direction and fitted in said bearing piece, a claw lever swingable around said pin and having a claw at its tip end, a spring member interposed between said claw lever and a large diameter portion formed on a clutch circumferential inside of said pin and urging said claw lever toward a clutch radial outside while allowing said claw lever to move toward a clutch radial inside, said claw lever being formed so that said claw of said claw lever mates with a ratchet tooth surface on said inside surface of said adjusting ring, a sensing arm extending in a clutch circumferential direction and connected to said claw lever, a sensing pin on said sensing arm extending radially inwardly of said clutch, said sensing pin having a tip end fitted in a groove formed on an outer peripheral part of said retainer with a pre-set axial play between said tip end and said retainer for permitting said sensing pin to swing in and around said pin.